The passage of small and large molecular weight substances across the blood-brain barrier (BBB) was investigated during development of biphasic ischemic edema in the brain. The initial increase in cerebral water content (first phase) preceded the increased BBB permeability to Evans blue albumin complex, RISA, dextran and sucrose. The BBB change for large molecular weight substances was transient and most likely responsible for additional brain swelling (second phase). Moreover, the facilitated transport of 2-deoxy-D-glucose was altered and included an increased passive diffusion of the hexose from blood to brain during the second phase of ischemic cerebral edema. BIBLIOGRAPHIC REFERENCE: Spatz, M., Fujimoto, T. and Go, G.K: Transport studies in ischemic cerebral edema. In Pappius, H.M. and Feindel, W. (Eds.): Dynamics of Brain Edema. Berlin Heidelberg, Springer-Verlag, 1976, pp. 181-186.